Do you want lot's of glitz, side-window and lights, or a sleek minimal design? You will also need to look at how big of a case you want, and the cooling capacity it has. Cases also come in various colors.
There are a lot of cases that come with power supplies, but these are sometimes generic (low quality) PSU's.
That's a great site... They have some cases for sale, that I've never seen before. Got a kick out of those flowery cases...would be a hippy's dream. LOL!